is your interface online?
ping <YOUR-IP>
i would try whether i have a connection to the intranet.
ping <IP>
then i would try whether i can reach the gateway
ping <GW-IP>
then i would try to ping something in the internet
ping www.something.com
error ?
check your DNS settings...
/etc/resolv.conf
try nslookup
nslookup www.something.com
look into the /etc/nsswitch.conf. is it like this?:
hosts: files dns
...
..
.
greetings Preßy